Schedlerj



T. S. BINDSCHEDLER. DEVICE FOR OPERATING ADDING MACHINES AND THE LIKE.

APPLICATION FILED OCT. 19, I917. 1,436,639. P en e Nov. 28, 1922.

3 SHEETS-SHEET I. j Z

T. s. BINDSCHEDL ER. DEVICE FOR OPERATING ADDING MACHINES AND THE LIKE.

APPUCATION FILED 081 I9, 1917.

Patented Nov. 28, 1922.

3 SHEETS-SHEET 2.

T. S. BINDSCHEDLER.

DEVICE FOR OPERATING ADDING MACHINES AND THE LIKE. APPLICATION FILED OCT. 19. 1917.

1,436,639. Patented Nov. 28, 1922.

3 SHEETSSHEET 3.

D a Q a 19/4 L //Y POO/V05. o

Patented Nov. 28, 1922.

UNITED STATES v 1,436,639 PATENT OFF-ICE.

THEODORE S. BINDSCHEDLER, OF DETROIT, MICHIGAN, ASSIGNOR TO BURROUGHS ADDING MACHINE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICH- IGAN.

DEVICE FOR OPERATING ADDING MACHINES AND THE LIKE.

Application filed October 19, 1917. Serial No. 197,511.

To all whom it may concern:

Be it known that I, THEODORE S. BIND- SOI-IEDLER, a citizen of Switzerland, residing at Detroit, in the county of lWayne and State of Michigan, have invented certain new and useful Improvements in Devices for Operating Adding Machines and the like, of which the following is a specification.

More specifically stated, my invention Iclates to solenoid apparatus for operating adding or other machines where a stroke of.

considerable length is required and one in which the force or draft is substantially the same from one end of the movement to the other. Prior to my invention it has been proposed to use magnets or solenoids for similar purposes, but the construction has been such that the power with which the core is drawn increasestowards the end of the stroke with the result that a considerable blow or hammer is given at the end of the stroke. It is the purpose of my invention to give an even pull throughout which, in fact, slightly diminishes at the end of the stroke. This I accomplish by the construction set forthin the claims at the end of this specification. I have shown in the drawings and described in the specification the preferred embodiment of my invention, but it is to be understood that the specific disclosure is for the purpose of exemplification only, and that the scope of the invention is defined in the followin claims in which I have endeavored to istinguish it from the prior art, so far as known to me, without, however, relinquishing or abandoning any portion or feature thereof.

Referring to the drawings, Fig. 1' is a horizontal longitudinal section partly inclevation, through a solenoid embod ing my invention; Fig. 2 a similar view ut with the movable parts in a different position; Fig. 3a section on the line 3--3 of Fig. 1 looking in the direction of the arrows; 4 a view similar to Fig. 1 of a modified form; Fig. 5 a vertical longitudinal central section of the same; Fig. 6 a transverse vertical section on the line 6-6 of Fig. 5;

and Fig. 7 a diagram showing the pull of that just described. In Fig. 4 the tubes 15 the solenoid during the movement of the core.

Each part is identified by the same'reference character wherever it occurs throughout the several views.

Referring first to that form of the invention shown in Fig. 1 the coil 8 is shown mounted upon a tube or hollow spindle 9 of non-magnetic material, said spindle having at its opposite ends heads 10, 11, which are of similar material. The head 11 is formed with perforated ears 12, 12, through which extend the rods 13, 13 by which said head is connected to a base 14. Dowels 49 keep-the coil in proper position. The head 11 is suitably spaced from the base 14 by tubes 15 surrounding the rods 13, and nuts 16 threaded upon the rods 13 coact with said tubes to maintain the proper relation of the head and base. Rods 13 extend beyond head ll to form guides for the movable core of the solenoid and for a further purpose which will presently appear. The movable or working core 17 of magnet materlal reciprocates within the tube 9 and is provided with a cross head 18 also of magnetic material to which are secured lugs 19- 19 of nonmagnetic material notched at 20- 20 to receive and slide upon the rods 13. A perforated lug 21 is connected to the head for attachment to the device to be operated by the solenoid.

The magnetic base 14 is bored in registry with the tube 9 and an idle core 22 extends through the bore at 23 into the tube 9. The idle core is formed with a long, tapering recess 24 to receive the similarly tapered The working core is shouldered at 29 and provided with a cushion 30 of leather or the like which latter has the effect of preventing the tapered endof the working core entering so far within the recess of the idle core as to stick either mechanically or because of magnetic attraction.

Referring now to Figs. 4, 5'and 6, it will be seen that the construction of the solenoid proper is substantially the same as are shown in section to more clearly illustrate the construction. The base plate 14' in this construction is secured to a casting of nonmagnetic material and is integral with longitudinal members 31-31 forming part of a frame comprising shoulders 3232, and an upturned bracket 33. The coil 8 is mounted between the base 14 and the'shoulders 32, the non;magnetic heads 10, 11'- being doweled to said base and shoulders respectively. A gap or opening 34 is formed between said shoulders and the cross-head '18 is formed to fit within said gap when the working core is in its inner position, said head in part overlapping the shoulders as at 35-35. Guide lugs 1919 of "insulating material are secured to the overlapping portions of the cross-head and notched at 20 to receive tlk guide rods or base by which it is secured to the crosshead, and said enlargement is chambered at 42 in communication with the bore of said sheath. The rack is shouldered at 43, which shoulder may be formed as shown, by making the rack of the rectangular section 4.4 and surrounding it by the cylindrical section 45, which terminates at the shoulder 4.3 and is rigidly connected to the rack action of the solenoid on the .erated thereby.

proper. Between the shoulder 43 and an inwardly turned shoulder 46 formed in the sheath, 9. spring 4L7'is compressed, the outward movement ofthe rack under the pressure of the spring being limited by a pair of nuts 48 screwed. upon the threaded end of the rack. By adjusting the nuts the pressure of the spring may be adjusted. Also the relative location between plunger and rack and its engaging sector maybe adjusted. Obviously the spring connection between the rack and head serves to cushion the mechanism op- When the coil is energized the lines of force extend through the magnetic circuit comprising the idle core, base 14, rods 13, cross-head 18 and working core 17. The only breaks in the magnetic circuit when the core is in an outer position are between the idle and working cores and between the crosshead on the working core and the guides 13 which as shown are of considerable cross-section to aiford a suitable magnetic field. The slender or elongated taper of the end of the working core and the corresponding recess in the idle core minimize the magnetic gap between the two and thereby increase the pull in the outer position of the core. This is further increased also by the location of the gap between the idle and working cores with reference to the head of ma coil as shown in the drawings. The heads 10, 11, lugs 19 and the sleeve 9 being of non-magnetic material do not affect the magnetic field nor cause the parts to stick. When the working core is in an outer position and the cross-head 18 substantially between the outer ends of the guide rods 13, there is practically no magnetic leakage. As the core and cross-head move in, however, and the latter leaves the ends of the rods 13, the ends of the latter establish magnetic poles and leakage occurs which increases as the cross-head moves inward away from the ends ofthe rods. By reason of this construction, therefore, the increase in pull due to the approach of the working and idle cores and which is minimized by the shape of the cores in substantially compen sated by the magnetic leakage from the rods 13, so that the pull of the solenoid is substantially the same in the inner position of the core as in the outer position. 7 of the drawings I have charted the curves of an ordinary solenoid and of my improved solenoid, curve A representing the former and curve B the latter. In this drawing is shown the tremendous increase in pull in the ordinary solenoid as the core approaches its final position, and" the action of my improved solenoid in which the pull is at a maximum in the intermediate position of the solenoid, the pull at either end of the stroke being substantially the same and but little more than the pull at intermediate points. .Another feature of advantage consists in the flange 27 of magnetic material on the idle core which greatly, increases the attraction between said core and the base 14, The idle core, except for magnetic attraction, is free to move and does move under the impact of the working core, or, rather. of the cushion thereon, against the end-of said idle core, but the attraction of the base for the idleco're is so great by reason of the flange on the latter that it yields only to the momentum of the working coreand thus cushions the stroke of the latter. -Washer 50 of nonmagnetic material prevents actual contact between flange 27 and base 14. Va-

riation in thickness of this washer furnishes means of controlling the amount ofmagnetic attraction between flange 27 andbase14.

I claim:

1. A solenoid comprising a coil, an idle core and a working core, a rod of magnetic 'materi'al in magnetic circuit with the idle core and substantially parallel to the line of movement of the workm core, and a crossnetic material on the working core adapte to travel along adjacent to said rod and to complete the magnetic circuit therethrough 2. A solenoid comprising a coil, an idle and a working core, abase of magnetic material in magnetic circuit with the working core, a guide of magnetic material substantially parallel to the axis of the coil, and a cross-head of magnetic material on the Working core movable along said guide to increase the magnetic leakage as the working core approaches the idle core.

3. A solenoid comprising a coil, a wor ing core and an idle core, a base of magnetic material, a pair of guides of magnetic material extending substantially parallel to the axis of the coil, and a cross-head of magnetic material on the Working core movable longitudinally of said guides and adapted to increase the magnetic leakage as the working core approaches the idle core.

4. Ina device of the class described, a coil, a magnetic base, an idle core, a pair of guide rods of magnetic material secured to and extending from said base, a cross-head of magnetic material on the working core, and guide lugs of diamagnetic material secured to the cross-head and engaging said guide rods.

5. In a device of the class described, a coil, a Working and an idle core, a magnetic base in magnetic contact with the idle core, a pair of guides of magnetic material extending parallel to the axis of the core, a cross-piece of diamagnetic material connecting the guides between which and the piece the coil is secured, a cross-head of magnetic material mounted on the working core and movable therewith and extending close to the guides, and lugs of non-magnetic material secured to the cross-head and engaging the'guides.

6. In a device of the class described, a'coil, a Working core movable therein, a cross-head of magnetic material on said core, a base of magnetic material. a pair of guides of magnetic material secured to the base and on which the cross-head reciprocates, an idle core reciprocably mounted in said base and extending into the coil, and a flange of magnetic material on said idle core arranged to engage said base.

7. In a device of the class described, a coil, a Working core, a base of magnetic material perforated in axial alignment with the coil and having a shouldered recess coaxial with the perforations, and an idle core reciprocable through said base and having a flange of magnetic material adapted to enter the recess in said base.

8. In a device of the class described, an idle and a working core, a base of magnetic material, a pair of guides of magnetic material attached to the base and extending substantially parallel to the axis of the coil, and a cross-head of magnetic material on the working core movable longitudinally of said guide to increase the magnetic leakage as the Working core approaches the idle core.

THEODORE S. BINDSCHEDLER 

